Door operator



Feb. 18, 1936. PARVIN L 2,031,226

' noon OPERATOR' Filed Aug. 8, 1934 INVENTOR Edward 6. Fh rm- ATTORNEYS;

Patented Feb. is, 1936 UNITED STATES PATENT OFFICE amaze nooa ornaa'roa a corporation of West Application sum a, 1934,8erial No. man

I 4 Claims.

, This invention relates to improvements in automatic power operated door mechanisms.

The basic object of this invention is to provide a power operated door controlled by a device, which. issubject to changes in electrostatic capacity produced by the presence ofa person's body in approaching the door. I The invention has manyobiects which will be more clearly understood from the following disclosure when taken in-connection with the attached drawing. p

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be more fully described in the following specification.

In the drawing the single figure is a diagrammatic view showing the combination of elements of this invention.

The arrangement is shown as applied to door operation. but it is, of course, apparent to those skilled in the'art that the system is adapted for controlling and operating many forms of devices. Thereisshowninthedrawingadoorframe I in which a door l'is mounted upon a vertical shaft 25 U which may rotate about a fixed vertical axis.

Supported over the door is a pneumatic motor 3 which is connected to the door shaft by the pivotallyinterconnected levers 4., This manner of operating doors and the interconnection of the, 30 partsissoverywell knowninsomanyformsthat it is believed that the diagrammatic illustration is suflicient. It may be noted at this point as willbeapparentto'thosesldlledintheart,that although a pneumatic motor is disclosed any other form of power device may be equally well 1 controlled and be employed for operating the door. .'Ihewalls.ldefinethepassagewayleadingto and from the doorway. Mounted upon these walls 4 inanysuitablemanner area'pairo'fmetal plates -'landlwhichextendbeyondthedoorsatboth sides the necessary distance so that the door will havetimetofullyopenbythetimeamoving pearson reaches it from either direction. These 45 metal platuareconnected by thewires l to a resistance ll. One terminal of this resistance is ccnnected tothe grid ll of athyratron vacuum device which is preferably of the mercury vapor type. The plate or anode il of thethyratron is 50 connected by wire I: to one terminal of the solenoid winding of an electromagnetic valve ll;

Itisalsoherenoted thattheelectromagnetlc valve and its association with a pneumatic motor is verywellknownintheart. Theothertermi- 55 nalofthesolenoidwindingoftheelectromagnetic valve is connected by wire II to one terminal of the primary .ll of a suitable transformer. Theother terminal oi the primary is connected by wire to one terminal of'the secondary is of the transformer and to thecathode I! of the 5 thermionic vacuum device. The primary of the transformer is energized. through the power supply wires and the switch II. The other terminal of the secondary is connected through a condenser II to that wire 0 which connects to the opposite end of resistance It from that which is connected to the grid. 7 28 represents the usual heater for such devices energized by a suitably proportioned winding it which may likewise comprise a part of the secondary of the transformer. 15 Thermicnic devices of this type are well known 1 in the art. When switch I. is closed the transformer is energized vwith the result that the heater 2! raises the temperature of the equi-potential cathode 22 to a point where it emits elecgo trons. The usual potential is present plate I! but the flow of electrons from the cathode totheplateisinten'uptedbythefact thatthere .is present a charge on the grid which blocks their flow. I g .25

It will be noted that the sridcircuit of the vacuum device includes the resistance ii, the in-v ductance of the secondary I, the condenser II and the condenser provided by the separated plate: I and l. The resistance, inductance and capacity of the grid circuit are so proportioned thatwhen there is no one between or-near the platesl andlthepotentialof'thegrid ll lssuch as to substantially completely block the passage of electrons from the cathode to the anode. 5 However. as soon as a person initially moves Ibetweenthe plates 1 and 8 in approaching the door thecapacityofthegridcircuitischanged.caus-' ingaphaseshiftwherebythegridnolongeracts toblock the flow of electrons to the plate and 40 thedevice'issetin operation. Theresult isthat acurrentiiowsintheplatecircuitofthevacmim device which includes the electromagnetic valve. The electromagnetic valve therefore operates to supplycompressedairtotheenginelsothatw 'thedoorope'ns. As-soonasthepersonpasses beyond the range of the condenser plates I and [the phase of the grid circuit shifts back to normalandablockingchargeisappliedtothe grid. The flowof current in the plate circuit immediately stops and the magnet valve returns to normal position, cutting oil the supply of fluidpressure'sothatthe'engine closes the door. It-may-benoted here that the 'engineillustratedisofthcdiiferentialtypewhere fluid pressure is always present in the smaller cylinder and the engine is moved back and forth by supplying compressed air to and exhausting it from the larger cylinder. This is likewise. very well known in the art. It is apparent that the standard type of engine may be employed, in which case the magnet valve is modified in accordance with well lmown principles so as to alternately supply fluid pressure to opposite ends of the engine and to exhaust fluid pressure from the other end. As noted above, this arrangement could equally well control an electric motor for operating the door.

The above described operation of the thermionic device is a description of the operation of that well known form of device which operates with what is popularly termed trigger action". No current flows in the plate circuit until the potential on the grid falls below acertain value when the device immediately goes into action and continues to operate until the potential on the grid is raised to a point completely blocking the plate circuit.

From the above description it will be apparent that this invention resides in certain principles of construction and operation which may be embodied by those skilled in the art in other forms without departure from the scope thereof. I do not, therefore, desire to be strictly limited to this disclosure,'but rather to the appended claims.

What I seek to secure by ,United States Letters 4 Patent is: r

being of sumcient length so that the door .is fully open when the person reaches it.

2. A door operating system as described comprising a movably supported door, power means connected to the door for moving it and control means for said power means including a pair of closed position, control means for the power def positioned with respect to the door so that the door is fully open when the person reaches it.

4. A door operating system as described com-- prising a movably supported door, a power device .connected to the door for moving it to open andv closed position, control means tor the power device having a balanced control circuit and a pair of metal plates extending from the door in the passageway thereof and connected to the balanced circuit so as to form an electric ileld therebetween, whereby a person approaching the door ;v

unbalances said circuit causing the door to be fully opened by the time he reaches it and to remain open as long as his presence in the passageway maintains the circuit unbalanced.

nnwann o. PARVIN. 

